Electric switch.



M. LEVISON.

ELEU IHIC SWITCH.

APPLICATION FILED JULY17,1911.

Patented Jan. 26, 1915.

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mmmw Q I MAUBICELEVISON, OF CHICAGO, ILLINOIS, ASSIGIIOR, DIRECT AND MESNE ASSIGNMENTQEO- CHICAGO SIGNAL COMPANY, OE? CHIGAGQ, ELIE-01S, A CORPORATION-0E ILLINOIS.

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Patented Jana 2(5, 1915,

Application filed m 17, 1911: Serial- No. ceases;

To all whom it may concern Be -it known th ati, MAURICE Lawson, a citizen of the United States, residing at Olricagog-in the county of Gook and State of Illnois, have invented certain new and useful'Improvements in ElectricSwitches,- of which-the iol-lowing is a specification.

My inventiona relates to improvements in electric switches; and i more particularly to signaling call devices for-hospital service:

that the call initiating'app'aratus be-ofa character easily operable by a patient that it *shal'l operate 5 to i set- -'a 1 signal which shall remain in set condition until 'it is' released;

and that the' release-may be effected only through mechanism at l the sen'ding *station operabiebfy the nurseorattendant whose at tendance-is demanded by-the call.-

One or the objects of tmyinvention is to provide an electrical" signaling system,-

' wherein the initiation of the call shall set signals-at the-patientsbed side; and th'edoor otth'e room, and if necessary; at a remotesigna'l-receiving station; 'which"shall not in volverelays in'the circuitsg andwhich shall dispense with the cord 'connectionsan'd push button switch usually provided for operation -by the patient to initiate-the call.

Other obfiects= of 1 my invention-'- are simplicity and economy in the appliances and the cooperative relations thereof; and still further objects of my invention will readily occur to those skilled in=the'art from the-following description take in conjunctioawith the accompanying d-rawings, wherein Figure l is a perspective'view'of a signal box; Fig. Qis a p'erspecti ve detai'l' of certain of the mechanism in modified form; Fig-"3" is a diagram'of one circuit andFigre is adiagram of amodifiedcircuit.

In general, my invention contemplates th'e'provisionat each signal initiating point, say adjacent each patients bedside, of 'a combined signal setting and release" switch operable by thepatient to set a" signal -(2'. 6., to-causeannunciation of a suitable electrical annunciator) and operable by the nurse to release th'e signal and prepare the-device for operationanew'by the patient Said switching-mechanism I arrange in circuit'connec trons including, as annunoiators; lamps '10- cated at sultable pomt's as*fori mstance by,

annunciators in energized parallel circuits,

without the operation of any relay. Speoifical ly, 10 indicates a box of suitable iornr; here1nshown asam'etailic casing,

shown-aswith a clip '11 for attachment to the postofa bed, said casing providing-a? rear wall, 12, and a peripheralwail13,'hav- In such signaling systems; itis important ing'. an opening 141 01" an operatingleve'rr parts *are'insulattid from the"box, said base having at'its top a shelf 19 on which is mounteda damp socket 20 to receive'a' lamp 21. Upon the insulating base are-provided a suitable-pluralityof contacts-22, herein" shownas three in: number,- indicated'at "22%" 22 and 22, arranged *for'codperation with a contact 'lever'23i" I prefer that the switch lever shall be spring-n ovedin one direction,

and manually-movabie in'the other direction to b'e la'tched' under 'sprin tension,"one of its movements being ccnt'rolied by the patient and the other movement controlled by the In the-form of construction shown in Fig; 1, 25-indi'catcs a handle applied di rectly' to the lever=23 for moving-it downward againstthe tension-ofits spring 27,

coiled around the pivot 28 for the lever; 30 indicates a latching'tooth upon the fillcrum end oi the lever 23*arranged for cooperation with a'-latch31-, pivoted as at 82,

and provided with an elevating spring 33- tendingxto 'throw the latch to position for engagement with thetooth 30. A pull cord 36 is connected to an insulating block 86 on the latch 31, and 1s run to a position convenientfor operation by the patient." In

this construction, whenthehandle 253s depressed by 'a -Ill1I'SG,"i)heCO11t2LCt lever 23' is moved outofcontact with the switch contacts 22, and islatched in depressed condition by the latc'h member 81, spring 27 being put under tension. Accordingly, when-the patient'ipulls the cord,' 25'; withdrawing the latch lever' fil 'from the -=tooth 30; the 0011- tact 23 springs upward into engagement with the knife switches 22 for circuit closure.

As a more refined construction, somewhat more'expensive, but advantageous in many particulars, I may provide in connection with a contact lever 23, a separate operating lever 24, on which the operating handle 25 is mounted, said lever 24 having a finger 24' arranged to extend below the contact lever 23 when both of said levers are depressed, so that the contact lever 23 may be elevated directly with the operating lever 24. A spring 26 is interposed between the two levers 23 and 24 to be put under tension when the lever 24 is depressed in advance of lever 23', and an elevating spring 27 is provided with an operating lever 24, and the latching lever 31 and its equipment are arranged as heretofore de scribed, and latch dog 37 is provided for maintaining the contact lever 23' in raised position, being pressed toward latching .position by a'spring 38 and arranged to be moved out of operative position by the finger 24 just as the operating lever 24 reaches its most depressed position. In consequence, it will be observed that when both levers 23 and 24 are depressed so that spring 27' is under tension, release of the latch 31 by the nurse frees both levers so that they rise together, throwing the operating lever 23 into association with itscontacts 22. Inthis position, it is latched by the dog 37, so that subsequently, when the nurse depresses the handle 25 of the operating lever, the contact lever 23' remains in raised position for the time being, spring 26 being put under tension owing to the relative depression of the operating lever with respect to the contact lever. Just as the operating lever reaches its lowest position, however, the finger 24 throws the dog 37 out of engagement with contact lever 23, thereby freeing the latter from restraint so that the spring 26 automatically restores the lever 23 to depressed position effecting a quick break action of the switch mechanism. Thus, it is insured that-the switches controlled by lever 23' shallremain closed until the operating leveris conditioned for another operation by the patient, and sparking of the contacts is minimized by quick break action so automatically insured.

In Fig. 3 of the drawings, wherein I have diagrammatically illustrated certain circuit connections appropriate to my system, 40 indicates a transformer for stepping down the voltage of an ordinary lighting circuit 41 which may be either a direct or an alternating current. 42 and 43 indicate two main wires run through the area to be supervised, and between which all of the annunciator devices are to be bridged. 21

' indicates the bed lamp, 45 indicates the respective door lamp of the room and 46 indi cates the pilot lamp, located in the nurses receiving'station. Where one pilot lamp 46 is to be employed for a plurality of rooms or wards, the arrangement may be as indicated in Fig. 3, a wire 48 being run from wire 43 adjacent the source of current supply 40, through the pilot lamp 46, to the several parallel branches 49, each of which is connected to one of the contacts, say 22, of each of the switch boxes 10. Bed lamp 21 is connected by wire 50 from the main wire 43 to another contact 22* for each individual box, and the door lamp 45, common to the ward, has one side connected to the main wire 43, its other side connected by parallel branches 52 to the remaining con tact 22 of the individual boxes 10 which it serves. The contact lever 23 under such circumstances has connection by wire 54 to the remaining main wire 42. It will now be ap- 1 parent that when one of the switches 23 is closed, parallel circuit paths are established through the several lamps, as follows: Through bed lamp '21 by path 43, 50, 21, 22 23, 54, 42; through the appropriate door lamp 45, by path 43, 45, 52, 22, 23, 54, 42; and through the common pilot damp 46, through the path 43, 46, 48, 49, 22 23, 54, 42 ;-only the bed lamp of the particular patient and the door lamp of the particular ward or room being lighted together with the pilot lamp common to the entire branch of the service.

Where an individual pilot lamp. and its third wire 48 is localized to one ward or room, connections may be made as indicated in Fig. 4, the switch members 23 being free from wire connection and wire 54 being connected to one of the contacts, say 22, of the switch. As before, the separate wire 48 for each pilot has parallel connection 49 to contacts 22 of all of the switches of the ward or the single switch of the individual room served by that pilot, and the bed lamp has its individual Wire 50 from the wire 43 to the contact 22*. The door lamp 45 for the ward or individual room may be connected by wire 52' between the third wire or pilot wire 48 and the main wire 43. Under such circumstances, it will be apparent that the closure of the switch of any. box 10 will bridge the individual lamp 21 between the main wires 43 and 42 by path 50, 21, 22*, 23, 22, 54; the pilot lamp by connection 48, 46, 49, 22 23, 22, 54; and the door lamp by connection 52, 45, 48, 49, 22 23, 22 54.

In each instance, it will be observed that all lamps are parallel with each other, so that the'incapacitating of any one lamp, as by burning out, does not afiect the remaining annunciators which respond to the operation of any switch, or'in other words, does no damage beyond elimination of the percentage of lamps injured.

meme t While I have hereindescribed in some detail a particular embodiment of my invention, which I believe to be useful in detail, it will be apparent to those skilled in the art that changes in the details of construction may be made without departure from the spirit of my invention and within the scope of the appended claim.

What I claim is':

In a switch the combination of a stationary contact, a switch blade edapted'toengage the contact, a control lever so posi tioned that on its extreme movement in one direction it coacts with the blade and presses the same into engagement with the contact,

' a spring resiliently holding the blade and control lever together, a second spring resiliently holding the control lever in. the afore mentioned extreme position, a latch for locking the control lever in its opposite extreme position, means for releasing said latch and a second latch for holding the switch blade in contact engaging position,

and means carried by the control lever for releasing said last mentioned latch.

In testimony whereof I hereunto set my hand in the presence of two Witnesses.

:MAR'Z' l ALLEN, /V. LINN ALLEN. 

